target/alpha: Replace legacy ld_phys() -> address_space_ld()

Prefer the address_space_ld/st API over the legacy ld_phys()
because it allow checking for bus access fault.

Since we removed the last legacy uses of the legacy ldst_phys()
API, set the TARGET_NOT_USING_LEGACY_LDST_PHYS_API variable to
hide the legacy API to alpha binaries, avoiding further API uses
to creep in.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20251224160040.88612-7-philmd@linaro.org>

configs/targets/alpha-linux-user.mak

@@ -4,3 +4,4 @@ TARGET_SYSTBL=syscall.tbl
 TARGET_LONG_BITS=64
 TARGET_XML_FILES= gdb-xml/alpha-core.xml
 TARGET_NOT_USING_LEGACY_NATIVE_ENDIAN_API=y
+TARGET_NOT_USING_LEGACY_LDST_PHYS_API=y

configs/targets/alpha-softmmu.mak

@@ -2,3 +2,4 @@ TARGET_ARCH=alpha
 TARGET_LONG_BITS=64
 TARGET_XML_FILES= gdb-xml/alpha-core.xml
 TARGET_NOT_USING_LEGACY_NATIVE_ENDIAN_API=y
+TARGET_NOT_USING_LEGACY_LDST_PHYS_API=y

target/alpha/helper.c

@@ -169,6 +169,7 @@ static int get_physical_address(CPUAlphaState *env, target_ulong addr,
                                 int prot_need, int mmu_idx,
                                 target_ulong *pphys, int *pprot)
 {
+    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
     CPUState *cs = env_cpu(env);
     target_long saddr = addr;
     target_ulong phys = 0;
@@ -176,6 +177,7 @@ static int get_physical_address(CPUAlphaState *env, target_ulong addr,
     target_ulong pt, index;
     int prot = 0;
     int ret = MM_K_ACV;
+    MemTxResult txres;
 
     /* Handle physical accesses.  */
     if (mmu_idx == MMU_PHYS_IDX) {
@@ -214,18 +216,13 @@ static int get_physical_address(CPUAlphaState *env, target_ulong addr,
 
     pt = env->ptbr;
 
-    /*
-     * TODO: rather than using ldq_phys_le() to read the page table we should
-     * use address_space_ldq() so that we can handle the case when
-     * the page table read gives a bus fault, rather than ignoring it.
-     * For the existing code the zero data that ldq_phys_le will return for
-     * an access to invalid memory will result in our treating the page
-     * table as invalid, which may even be the right behaviour.
-     */
-
     /* L1 page table read.  */
     index = (addr >> (TARGET_PAGE_BITS + 20)) & 0x3ff;
-    L1pte = ldq_phys_le(cs->as, pt + index * 8);
+    L1pte = address_space_ldq_le(cs->as, pt + index * 8, attrs, &txres);
+    if (txres != MEMTX_OK) {
+        /* bus fault */
+        goto exit;
+    }
 
     if (unlikely((L1pte & PTE_VALID) == 0)) {
         ret = MM_K_TNV;
@@ -238,7 +235,11 @@ static int get_physical_address(CPUAlphaState *env, target_ulong addr,
 
     /* L2 page table read.  */
     index = (addr >> (TARGET_PAGE_BITS + 10)) & 0x3ff;
-    L2pte = ldq_phys_le(cs->as, pt + index * 8);
+    L2pte = address_space_ldq_le(cs->as, pt + index * 8, attrs, &txres);
+    if (txres != MEMTX_OK) {
+        /* bus fault */
+        goto exit;
+    }
 
     if (unlikely((L2pte & PTE_VALID) == 0)) {
         ret = MM_K_TNV;
@@ -251,7 +252,11 @@ static int get_physical_address(CPUAlphaState *env, target_ulong addr,
 
     /* L3 page table read.  */
     index = (addr >> TARGET_PAGE_BITS) & 0x3ff;
-    L3pte = ldq_phys_le(cs->as, pt + index * 8);
+    L3pte = address_space_ldq_le(cs->as, pt + index * 8, attrs, &txres);
+    if (txres != MEMTX_OK) {
+        /* bus fault */
+        goto exit;
+    }
 
     phys = L3pte >> 32 << TARGET_PAGE_BITS;
     if (unlikely((L3pte & PTE_VALID) == 0)) {